Patient monitoring has become prevalent both inside and outside of a hospital, allowing physiological parameters of a patient to be monitored. Sensors utilized to collect these physiological parameters include electrocardiogram (ECG) circuitry, accelerometers, respiration sensors, etc. Physiological parameters monitored may include cardiac rhythm, activity level, posture, breathing rate, and others. In particular, cardiac monitoring of patients both inside and outside of a hospital has become more prevalent, with cardiac devices/monitors being utilized to detect arrhythmic conditions (e.g., any abnormality or perturbation in the normal electrical rhythm of the heart). Examples of arrhythmias include premature atrial contractions, premature ventricular contractions, atrial fibrillation, atrial flutter, ventricular tachycardia, ventricular fibrillation, bradycardia, and others. Cardiac arrhythmias may be accompanied by symptoms, or by no symptoms at all. Similarly, other types of monitoring devices may be utilized to detect other patient conditions.
Detection of abnormal conditions typically requires analysis of the monitored physiological parameter and comparison to a trigger criteria. Satisfaction of the trigger criteria typically results in at least a portion (i.e., segment) of the monitored physiological parameter being stored and/or communicated to a healthcare professional (HCP) for review. For diagnostic purposes, it may be beneficial to include in the captured segment the onset of the abnormal condition (e.g., the monitored physiological signal just prior to onset of the abnormal condition). This information may be valuable in diagnosing the cause or abnormal condition. Likewise, it may be beneficial to include in the captured segment (or subsequently captured segment) the offset of the abnormal condition (e.g., the monitored physiological signal following the offset or send of the abnormal condition). However, the capture of segments of monitored physiological parameters in response to a trigger criteria typically relies on a predetermined duration of time prior to and following the trigger event. With the various types of physiological parameters and various trigger criteria being utilized (both of which affect the duration of time required to trigger capture of an event), it is difficult to ensure that the onset/offset of the abnormal condition is captured.